1. Field of the Invention
The present invention relates to a linear vibrator for generating vibration by causing a vibrating body, which is elastically installed in a housing, to be in a translational motion, and more particularly to a surface-mountable linear vibrator, in which a substrate member is fixed to a lower part of a housing.
2. Description of the Related Art
Various kinds of vibration generators for generating vibration, serving as an incoming call destination signal, are installed in mobile communication terminals, i.e., mobile phones. Vibrating motors are generally used as the above vibration generators. Each of the vibrating motors converts electrical energy to mechanical energy, and rotates an eccentric weight using the mechanical energy, thereby generating vibration.
FIG. 1 is a cross-sectional view of a conventional coin-type vibrating motor 100, which is used as a vibration generator.
As shown in FIG. 1, the conventional coin-type vibrating motor 100 comprises a rotor assembly 110, a stator assembly 130, and a housing 102 for accommodating the rotor assembly 110 and the stator assembly 130.
Here, the rotor assembly 110 includes a winding coil 114, a commutator 116, and a weight body 118. The winding coil 114 and the weight body 118 are installed on an insulating body 112, and the insulating body 112 is rotatably installed on a shaft 122, which is vertically placed in the housing 102.
An upper substrate 124 is attached to the lower surface of the insulating body 112, and the commutator 116, including a plurality of segments divided and spaced from each other by a constant interval in a circumferential direction, is attached to the lower surface of the upper substrate 124. Here, the commutator 116 is electrically connected to the winding coil 114.
The stator assembly 130 includes a bracket 132, a magnet 134, and a brush 136.
That is, as shown in FIG. 1, a lower substrate 135 is fixed to the upper surface of the bracket 132, and the lower part of the bracket 132 is bonded to the lower part of the housing 102 having an opened lower surface. The magnet 134 having a disk shape and the brush 136 are fixed to the upper surface of the lower substrate 135, and the brush 136 is electrically connected to an external power source through the lower substrate 135.
When the bracket 132 is attached to the lower part of the housing 102, the upper end of the brush 136 contacts the commutator 116, thereby supplying current to the winding coil 114 through the commutator 116.
A power supply unit 140 including anode and cathode terminals 142a and 142b and lead wires 144a and 144b is installed on the lower substrate 135, and is electrically connected to the external power source. That is, the lower substrate 135 includes a terminal 135a protruded to the outside of the housing 102, and the anode and cathode terminals 142a and 142b are installed on the upper surface of the terminal 135a. The lead wires 144a and 144b electrically connected to the external power source are electrically connected to the anode and cathode terminals 142a and 142b. 
Accordingly, a current from the external power source is supplied to the brush 136 of the vibrating motor 100 through the lead wires 144a and 144b and the anode and cathode terminals 142a and 142b, thereby rotating the rotor assembly 110 using the interaction between the winding coil 114 and the magnet 134, and thus generating vibration.
Here, since the commutator 116 of the rotor assembly 110 includes a plurality of the segments, when the rotor assembly 110 is rotated, the commutator 116 contacts the upper end of the brush 136. Thereby, mechanical friction and electrical sparks between the brush 136 and the commutator 116 are generated, thus damaging the brush 136 and the commutator 116.
As a result, the vibrating motor 100 has deteriorated endurance, and a shortened lifespan.
Since the rotor assembly 110 of the vibrating motor 100 is rotated centering on the shaft 122, the housing 102 requires a space necessary for the rotation of the rotor assembly 110. Thus, the vibrating motor 100 cannot satisfy the miniaturization trend, and has a limit in serving as a vibrating generator for mobile phones, which are gradually miniaturized.
In case that the vibrating motor 100 is installed in a mobile phone, the vibrating motor 100 is disadvantageous in that the mobile phone requires a separate space for receiving the power supply unit 140 installed on the terminal 135a protruded to the outside of the housing 102 and the lead wires 144a and 144b are connected to the external power source.
The lead wires 144a and 144b are electrically connected to the external power source by soldering. At this time, failures in soldering cause disconnection or short circuits of the lead wires 144a and 144b, thereby increasing a failure rate of the mobile phone.
Since the available space in the mobile phone is small, it is not easy to handle the lead wires 144a and 144b. 